Boiler and furnace



v Nov. 17, 1931. o. DE LoRENzl L332103 BOILER AND FURNAE Filed Jan. 14, 1929 E22 C S- az-- 32 INVE TOR @95 MMW ATTORNEYS Patented Nov. 17, 1931 narran STATES PATENT orFicE v g oTTo DE LoRENzI, E MArLEwoon, NEW JERSEY,- AssIeNoR To INTERNATIONAL cour-A EUsTroN ENGINEERING CORPORATION, 0E NEW YQRK, N. Y., a CORPORATION 0E DELAWARE BOILR AN D FURNAGE Application filed. January 14, 1929. Serial No. 332,243.

This invention relates to boilers and furnaces, and is especially useful where the fuel is employed in finely divided form, such, for example, as pulverized coal.

Onevof the 'objects of the invention is to prevent the slaggingof refuse in an improved manner. l Y Another object of the invention is to make it possiblevto operate at very high `ratings indeed, without'encountering difficulties of the character hereinafter pointed out.

Still anotherobject of the invention resides in the'provision of an arrangement ofl boiler and a water wallv lined combustionchamber therefor in such a wayy asl to secure'effective circulation. l

More specifically it is an object-,of my invention to provide anovel arrangement of cooling tubes for the bottom of a pulverized coal burning furnace.

How the foregoing, together with such other objects and advantages as may hereinafter appear, or are incident to my invention, are realized as illustrated in the accompany ing drawing, ingwhich- Y The figure is a vertical sectionthroughthe preferred form of my invention;

kReferring now to thefigure, the reference character A denotes the boiler proper and B the combustion chamber therefor. The boiler is of the double Ladd type and embodies two units` a, b, each having an upper steam and waterdrum 7, a lower mud drum 8 and three banks of connecting tubes 9, 10, and 11, the units being set opposite one another and above the combustion chamber B so that the gaseous products of combustion from the latter rise in the space between the two units and traverse the units in lpasses provided by the 'baffling shown. A common steam drum 12 is located above the plane of the drums v7 and is conportions 15, .16 and-17. The lower ends of the tubes of-these portions connect with the headers 18 located externally of the combustion chamber; the upper ends of the portions 15 and17 connect into the headers 19 and 20; and vthe'upper ends of the tubes ofthe portions 16 connect into the header 21 located -exteriorly of the combustion chamber.

The header 18 is supplied by outside downcomers `22 each of which, at thebottom, has

a plurality of'small pipes 22"CODl1eCtDg the lower ends of the downcomers 22 with the header 18. leads from the steam and water drum 7 of vone of the units and the other downcomer from the steam and water drum 7 of the otherunit. The header 18 is also supplied by la group-of downcomers`23 leading from the mud drum 8 of one unit and a similar group of downconiers 23 leading from the mud drum of the other unit. The header 18 is also supplied by a portion ofthe tubes 24 Aof the row of tubes 25, the upper .ends of which areiconnected with the mud drumV 8 of one unit. There-is another row of such tubes v25 leading downwardly from the mud drum of the other unit anda number'of such tubes 24 connected with the header 18. The remainder of the tubes of each row of tubes 25 leadfto the header 26 located outside of the bottom of the combustion chamber, this bottomgbeing in he form of a double hopper. The lowerend portions ofthe tubes which connect with the hcader 26 extend inwardly and downwardly and pass through the hoppers a short distance above the bottoms thereof.

Ata higher level I provide a slag screen C composed of two rowsof horizontally inclinedtubesv 27 and 28. The tubes 27 incline inwardly and downwardly from the header 29 to about the middle of'the combustion chamber and thence they bend downwardly to pass outsideof the combustion chamber to connect `with the header 26'. Similarly,- the tubes 28 extend inwardly and downwardly from the header 80 for connection with the header 26. The tubes 27 and 28 are laterally spaced ,from one another so as to permit gravitating ash'to freely 'pass through the One of these downcomers 22 space therebetween into the hoppers. Similarly, the tubes therebelow are spaced for the same purpose. Preferably the tubes 27 and 28 have'their inner ends extended past one another so as to give maximum cooling effect near the center of the combustion chamber.

Rising from the header 29 is a water wall composed of a row of tubes 31, the upper ends of which tubes are connected into the header 32, which header, in turn, has connected` thereto the lower ends of the arch tubes .33, which tubes serve to support the arch 34 and to line the throat 35. The upper ends of the tubes 33 are connected with tubes of the banks of tubes of the left hand unit by means of the connectors 36 inside the drum 8 of that unit.

There is a similar water wall of tubes 31 rising from the header to the header 32 from which arch tubes 33, as before, lead for delivery to tubes of one of the banks of tubes of the other unit. Y

I Vprefer to have the arch tubes connected with the irst row of the second bank of tubes. The headers 21 of the side water walls .are connectediby risers 37 to the steam and water drums? of the two units.

Y From the foregoing it will be seen that i water supply for the screens and water walls is taken not only from the steam andy water drums, but also from the mud drums; and

that the delivery from the water walls is divided, approximately half going to one of the steam and water drums and the other half to the other steam and water drum.

It will also be observed that I use a portion of the downcomers for the slag screen as a "means for further cooling refuse by the absorption ofV heat from the bottom of the cornbustion chamber. I am enabled to do this without incurring any circulation diiiiculties byvirtue of the high head of water above the header 26 which is practically the low point of the entire installation. v

By utilizing thesev downcomers for ei'ecting cooling, I am enabled to operatel at extremely highrates without causing. fusion of the refuse into a molten mass dicult to remove without shutting down the furnace. The space which must Vnecessarily'be provided between the tubes 27 and 28 imposes a limitation upon the number of tubes that can be employed, and, of course, ythe cooling effect of such tubes is dependent upon 'their number. Hence, such tubes, of themselves, are insufficient to secure the .desired cooling of the refuse when operating at extremely high rates. Y

Owing to the'large number of tubes inthe installation subject to radiant heat, a great proportion of the steamis generated insuch tubes, and there is very rapid circulation therethrough. The taking of the water supply for such tubes in part from the steam and water drums and in part from the mud drums ensures the maintenance of proper water.

levels in the steam and water drums, cuts down the ebullition, and tends to secure the delivery of drier steam to the steam drum 12.

The fact that there is a rapid circulation and a heavy pull through the upright water walls connected with the slag screen assists in making it possible to use the downcomersas a cooling means in the bottom of the furnace.' p

The 'furnace may be tired downwardly through the arches or by means of burners located at the corners preferably in the lower part of the combustion chamber and arranged to fire tangentially.

1. In combination, a substantially upright boiler, a combustion chamber therefor therebelow, a slag screen above the bottom of the chamber for cooling refuse Vcomprising two rows of spaced tubes, each row extending inwardly and downwardly from one of two opposite sides of the chamber ,to about the center there-of and to the exterior, a header for thelower ends ot ythe said tubes, upcomer means leading from' the upper ends of said tubes to the boiler, and downcomer means from the boiler .to said header comprising tubes arranged belovvvtheslag screen tubes to absorb heat to assist in cooling refuse.

2. In combination, a double Ladd type of boiler, each unit having an upper drum and a lower'drum with connecting tube banks, a combustion chamber below, upright .water wall tubes defining the tour'upright sides of the chamber, upcomer' connections therefor dividing the delivery from such tubes between the two upper drums and delivering to steam space thereof, and downcomer means thereforconnected to supply part of the water walls from the'upper and the lower drums of one unit and to-supply the other remaining part from the upper and lower drums of the other unit, together with a steam drum common to both upper drums.

3. In combination, a combustion chamber, a substantially upright boiler disposed at least in part above thechamber-and having water header means arranged adjcent the *top of the chamber, a slag screen for cooling ing said tubes with the boiler, and downcomer means leading downwardly from said header means tothe low point of said tubes,

said downcomer means being disposed partly within the chamber in position to assist -in cooling refuse.

4. v In combination, a combustion chamber, a. substantially upright-boiler disposed at least in part -above the chamber and having water header means arranged adjacent the top of the chamber, a slag screen forcooling refuse particles including a row of spaced tubes in the lower part of the charnber above the bottom thereof, upcomer means connecting said tubes with the boiler, and downconier means leading downwardly from said header means to the low point of said tubes, said Y d-owncomer means having portions inclined downwardly with respect to the direction of circulation therethrough, and said portions being disposed within the chamber in position to assist in cooling refuse and being connected with said tubes adjacent the low point thereof.

In testimony whereof I have hereunto signed my naine.

OTTO Dn LORENZI. 

